Modelling of spatially and temporally-varying cavity pressures in air-permeable, double-layer roof systems

J.H. Oh, G.A. Kopp

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)

Abstract

This paper discusses the development of an analytical model to simulate time-varying pressure distributions (Cpi) in the cavity of air-permeable layer, double-layer systems, given pressure data on the external surface (Cpe). The model was derived considering the pressure drops associated with the flow through the gaps between panels, which is like an orifice flow, and the cavity flow between parallel plates. Thus, the model uses two primary equations: the unsteady discharge equation and the equation for unsteady flow between two parallel plates. The model accounts for several geometric parameters including the gap (G) between the panels, the height (H) of the panel above the airtight layer and the length (L) of the panels, as well as the loss coefficients for the orifice and cavity flows. The proposed model is able to capture the fluctuations of Cpi and a good agreement is found between the numerical and experimental results for the mean, RMS and peak coefficients, to a great extent, when spanwise-averaged external pressure coefficients are used as input. For large gap-to-height ratios (i.e., G/H = 12.5), the model accuracy decreases.
Original languageEnglish
Pages (from-to)135-150
Number of pages15
JournalBuilding and Environment
Volume82
Early online date19 Aug 2014
DOIs
Publication statusPublished - Dec 2014

Keywords

  • Discharge equation
  • Pressure equalization
  • Air-permeable cladding
  • Wind loads

Fingerprint

Dive into the research topics of 'Modelling of spatially and temporally-varying cavity pressures in air-permeable, double-layer roof systems'. Together they form a unique fingerprint.

Cite this